The present invention relates to retractable canopy systems for boats, and more particularly to an improved manually-operated canopy deployment system wherein a pair of spring-loaded telescoping tubular actuators are assembled and connected in parallel alignment within a self-supporting framework to deploy a flexible canvas with a gear box to control the telescopic movement of the actuators and provide lightweight and readily mountable sunshade protection on a variety of boat structures.
In recreational boating, the so-called “bimini top” is a convertible cover erected upon the deck of the boat and made to be deployed at an elevation comfortably above the heads of the passengers. Drawing its name from the Bimini islands in the Bahamas where it was first employed by boaters to provide desired shade from the strong rays of the tropical sun, the standard type of bimini top and those convertible boat covers of the same nature generally comprise a flexible canvas material secured to a foldable support frame that is erected across the deck and pivotally attached thereto. These standard types of foldable bimini tops can be raised when needed or lowered into a substantially flat position upon the deck when not in use or when an overhead obstruction may otherwise require its lowering. While deployment of these folding type bimini tops was often done manually, some were designed to be automated in their operation, the latter requiring electrical power, such as those described in U.S. Pat. Nos. 6,209,477 to Briedenweg and 6,983,716 to Ankney et al. Regardless of their specific foldable structure or method of operational deployment, the installation and utilization of bimini tops have became increasingly important for the protection of passengers and crew on board boats against excessive sun exposure and the known risks of skin cancer caused thereby.                While providing effective sunshade protection, the assembled structure of these folding bimini top arrangements, typically including a plurality of poles or bow-like members pivotally mounted across the boat deck, would often obstruct a person on board from reaching out over the side of the boat when fishing, docking or mooring the boat and further present an obstacle in boarding and loading equipment onto the deck. To overcome these obstacles and still provide effective sunshade protection, retractable canopy systems were devised and developed as retrofits for recreational boats capable of operative attachment to existing overhead structure on the boat without causing obstructions upon the deck. As retrofits, such retractable canopy systems were designed to mount onto existing rooftop members set over the deck of a boat or upon other elevated structures, such as radar arches or towers. These prior art retrofit canopy systems include those designed to be manually operated, such as those described in U.S. Pat. Nos. 4,951,594 to Feikama and 6,439,150 to Murphy et al., and those designed to be automated in their operation, such as that described in U.S. Pat. No. 7,571,691 to Russikoff. While these prior art canopy systems have been generally satisfactory in their intended manual or automated deployment upon boats, some drawbacks have arisen in their implementation and usage. The automated systems, for example, while providing relatively quick and easy deployment in a self-supporting framework, are rather burdensome in the weight of their assembled components, particularly those involved in their powered operation, and further in amount of retrofit labor involved in the mounting and routed connections these automated systems require. The manual systems, on the other hand, while being generally lighter in weight and more simple in their retrofit attachments than the automated systems, have been somewhat limited in their operational deployment upon existing rooftops of recreational boats and in providing extended sunshade protection therefrom in a relatively easy and efficient manner.        
Accordingly, there is a need for a new and improved canopy deployment system for recreational boats that is self-supporting in its structure and easy to mount and implement on virtually any style boat so as to provide relatively quick and efficient sunshade protection whenever necessary. Furthermore, there is an associated need for such an improved canopy deployment system to be relatively inexpensive to construct and assemble and be affordable to a substantial number of boat owners.